Unit 1 Test

Question 1

Which is not a reason why measurements are important?

Answer 1

They give us an absolute analysis of the world around us.

Question 2

Which is not an mks unit?

Answer 2

centimeter

Question 3

How are seconds defined?

Answer 3

They are based on the time it take cesium atoms to vibrate.

Question 4

How is a kilogram defined?

Answer 4

by a platinum brick in Europe

Question 5

Which is the definition of a derived unit?

Answer 5

A unit which is based on other (basic) units.

Question 6

How many significant figures are in the quantity

9.86 m/s ^2?

Answer 6

3

Question 7

What is the difference between a vector and a scalar?

Answer 7

A vector has both magnitude and direction; scalars have only magnitude

Question 8

Which of the following is not an example of a vector?

Answer 8

mass

Question 9

If the x-component of a vector is 3 and the y-component is 4, what is the magnitude of the vector?

Answer 9

5

Question 10

If V A + V B = V C which of the following is not true?

Answer 10

|A| + |B| = |C|

Question 11

If vector A makes an angle of 37 degrees with the x-axis and has a length Ax=12, what is the length of Ay?

Answer 11

9

Question 12

Which of the following is the sign of the scalar product of two vectors that have an angle of 79° between them?

Answer 12

positive

Question 13

What do you obtain if you calculate the following product of 3 vectors: A(B*C)? (Assume that vectors B and C are not at right angles to one another.)

Answer 13

a vector

Question 14

What is the scalar product of two perpendicular vectors?

Answer 14

What is the scalar product of two perpendicular vectors?

Question 15

Which is not true?

Answer 15

Vector products and scalar products both change sign for angles greater than 90°.

Question 16

Which of the following results from (AB)C, where A, B, and C are all vectors?
(Assume that none of the cross products results in zero.)

Answer 16

a vector

Question 17

Torque is given by the formula, t = F*d, where F is a force and d is a displacement. Which of the following is the magnitude of torque resulting from a 2.4 N force applied 17cm from the point of rotation, if the force is applied perpendicular to the displacement vector?

Answer 17

0.41 N⋅m

Question 18

If the cross product of a vector of length 5 and a vector of length 3 results in a vector of length 10, what is the angle between them?

Answer 18

42°

Question 19

If a vector pointing toward the north is crossed with one pointing toward the east, the resulting vector is pointing ____________.

Answer 19

down

Question 20

If a vector of magnitude 12 pointing in the x-direction is vector multiplied by a vector of magnitude 6 pointing in the y-direction, what is the magnitude of the resulting vector?

Answer 20

72